tonight as the obama administration considers its response, u.s. warships are on alert in the mediterranean near syria. we have two reports beginning with nbc's aymam moye yell dean is in cairo. >> doctors treated more than 31 patients wednesday out of which more than 350 died as a result. now all of them they say displayed symptoms of neurotoxicity, an indication that perhaps chemical weapons were actually used. the syrian government has denied any responsibility and denied that it used chemical weapons, more importantly today on syrian state television they showed images of chemical weapons that were allegedly found in areas that were controlled by syrian rebels, an indication that perhaps it was the rebels that were responsible for launching these weapons. meanwhile, the top u.n. disarmament chief, the undersecretary-general for the united nations arrived in damascus. she's been trying to press the syrian government to give u.n. inspectors access to the site of attacks so they can determine exactly what happened. as the u.s. and other countries